/* The Editor object manages the content of the editable frame. It
 * catches events, colours nodes, and indents lines. This file also
 * holds some functions for transforming arbitrary DOM structures into
 * plain sequences of <span> and <br> elements
 */

var internetExplorer = document.selection && window.ActiveXObject && /MSIE/.test(navigator.userAgent);
var webkit = /AppleWebKit/.test(navigator.userAgent);
var safari = /Apple Computer, Inc/.test(navigator.vendor);
var gecko = navigator.userAgent.match(/gecko\/(\d{8})/i);
if (gecko) gecko = Number(gecko[1]);
var mac = /Mac/.test(navigator.platform);

// TODO this is related to the backspace-at-end-of-line bug. Remove
// this if Opera gets their act together, make the version check more
// broad if they don't.
var brokenOpera = window.opera && /Version\/10.[56]/.test(navigator.userAgent);
// TODO remove this once WebKit 533 becomes less common.
var slowWebkit = /AppleWebKit\/533/.test(navigator.userAgent);

// Make sure a string does not contain two consecutive 'collapseable'
// whitespace characters.
function makeWhiteSpace(n) {
  var buffer = [], nb = true;
  for (; n > 0; n--) {
	buffer.push((nb || n == 1) ? nbsp : " ");
	nb ^= true;
  }
  return buffer.join("");
}

// Create a set of white-space characters that will not be collapsed
// by the browser, but will not break text-wrapping either.
function fixSpaces(string) {
  if (string.charAt(0) == " ") string = nbsp + string.slice(1);
  return string.replace(/\t/g, function() {return makeWhiteSpace(indentUnit);})
	.replace(/[ \u00a0]{2,}/g, function(s) {return makeWhiteSpace(s.length);});
}

function cleanText(text) {
  return text.replace(/\u00a0/g, " ").replace(/\u200b/g, "");
}

// Create a SPAN node with the expected properties for document part
// spans.
function makePartSpan(value) {
  var text = value;
  if (value.nodeType == 3) text = value.nodeValue;
  else value = document.createTextNode(text);

  var span = document.createElement("span");
  span.isPart = true;
  span.appendChild(value);
  span.currentText = text;
  return span;
}

function alwaysZero() {return 0;}

// On webkit, when the last BR of the document does not have text
// behind it, the cursor can not be put on the line after it. This
// makes pressing enter at the end of the document occasionally do
// nothing (or at least seem to do nothing). To work around it, this
// function makes sure the document ends with a span containing a
// zero-width space character. The traverseDOM iterator filters such
// character out again, so that the parsers won't see them. This
// function is called from a few strategic places to make sure the
// zwsp is restored after the highlighting process eats it.
var webkitLastLineHack = webkit ?
  function(container) {
	var last = container.lastChild;
	if (!last || !last.hackBR) {
	  var br = document.createElement("br");
	  br.hackBR = true;
	  container.appendChild(br);
	}
  } : function() {};

function asEditorLines(string) {
  var tab = makeWhiteSpace(indentUnit);
  return map(string.replace(/\t/g, tab).replace(/\u00a0/g, " ").replace(/\r\n?/g, "\n").split("\n"), fixSpaces);
}

var Editor = (function(){
  // The HTML elements whose content should be suffixed by a newline
  // when converting them to flat text.
  var newlineElements = {"P": true, "DIV": true, "LI": true};

  // Helper function for traverseDOM. Flattens an arbitrary DOM node
  // into an array of textnodes and <br> tags.
  function simplifyDOM(root, atEnd) {
	var result = [];
	var leaving = true;

	function simplifyNode(node, top) {
	  if (node.nodeType == 3) {
		var text = node.nodeValue = fixSpaces(node.nodeValue.replace(/[\r\u200b]/g, "").replace(/\n/g, " "));
		if (text.length) leaving = false;
		result.push(node);
	  }
	  else if (isBR(node) && node.childNodes.length == 0) {
		leaving = true;
		result.push(node);
	  }
	  else {
		for (var n = node.firstChild; n; n = n.nextSibling) simplifyNode(n);
		if (!leaving && newlineElements.hasOwnProperty(node.nodeName.toUpperCase())) {
		  leaving = true;
		  if (!atEnd || !top)
			result.push(document.createElement("br"));
		}
	  }
	}

	simplifyNode(root, true);
	return result;
  }

  // Creates a MochiKit-style iterator that goes over a series of DOM
  // nodes. The values it yields are strings, the textual content of
  // the nodes. It makes sure that all nodes up to and including the
  // one whose text is being yielded have been 'normalized' to be just
  // <span> and <br> elements.
  function traverseDOM(start){
	var nodeQueue = [];

	// Create a function that can be used to insert nodes after the
	// one given as argument.
	function pointAt(node){
	  var parent = node.parentNode;
	  var next = node.nextSibling;
	  return function(newnode) {
		parent.insertBefore(newnode, next);
	  };
	}
	var point = null;

	// This an Opera-specific hack -- always insert an empty span
	// between two BRs, because Opera's cursor code gets terribly
	// confused when the cursor is between two BRs.
	var afterBR = true;

	// Insert a normalized node at the current point. If it is a text
	// node, wrap it in a <span>, and give that span a currentText
	// property -- this is used to cache the nodeValue, because
	// directly accessing nodeValue is horribly slow on some browsers.
	// The dirty property is used by the highlighter to determine
	// which parts of the document have to be re-highlighted.
	function insertPart(part){
	  var text = "\n";
	  if (part.nodeType == 3) {
		select.snapshotChanged();
		part = makePartSpan(part);
		text = part.currentText;
		afterBR = false;
	  }
	  else {
		if (afterBR && window.opera)
		  point(makePartSpan(""));
		afterBR = true;
	  }
	  part.dirty = true;
	  nodeQueue.push(part);
	  point(part);
	  return text;
	}

	// Extract the text and newlines from a DOM node, insert them into
	// the document, and return the textual content. Used to replace
	// non-normalized nodes.
	function writeNode(node, end) {
	  var simplified = simplifyDOM(node, end);
	  for (var i = 0; i < simplified.length; i++)
		simplified[i] = insertPart(simplified[i]);
	  return simplified.join("");
	}

	// Check whether a node is a normalized <span> element.
	function partNode(node){
	  if (node.isPart && node.childNodes.length == 1 && node.firstChild.nodeType == 3) {
		var text = node.firstChild.nodeValue;
		node.dirty = node.dirty || text != node.currentText;
		node.currentText = text;
		return !/[\n\t\r]/.test(node.currentText);
	  }
	  return false;
	}

	// Advance to next node, return string for current node.
	function next() {
	  if (!start) throw StopIteration;
	  var node = start;
	  start = node.nextSibling;

	  if (partNode(node)){
		nodeQueue.push(node);
		afterBR = false;
		return node.currentText;
	  }
	  else if (isBR(node)) {
		if (afterBR && window.opera)
		  node.parentNode.insertBefore(makePartSpan(""), node);
		nodeQueue.push(node);
		afterBR = true;
		return "\n";
	  }
	  else {
		var end = !node.nextSibling;
		point = pointAt(node);
		removeElement(node);
		return writeNode(node, end);
	  }
	}

	// MochiKit iterators are objects with a next function that
	// returns the next value or throws StopIteration when there are
	// no more values.
	return {next: next, nodes: nodeQueue};
  }

  // Determine the text size of a processed node.
  function nodeSize(node) {
	return isBR(node) ? 1 : node.currentText.length;
  }

  // Search backwards through the top-level nodes until the next BR or
  // the start of the frame.
  function startOfLine(node) {
	while (node && !isBR(node)) node = node.previousSibling;
	return node;
  }
  function endOfLine(node, container) {
	if (!node) node = container.firstChild;
	else if (isBR(node)) node = node.nextSibling;

	while (node && !isBR(node)) node = node.nextSibling;
	return node;
  }

  function time() {return new Date().getTime();}

  // Client interface for searching the content of the editor. Create
  // these by calling CodeMirror.getSearchCursor. To use, call
  // findNext on the resulting object -- this returns a boolean
  // indicating whether anything was found, and can be called again to
  // skip to the next find. Use the select and replace methods to
  // actually do something with the found locations.
  function SearchCursor(editor, pattern, from, caseFold) {
	this.editor = editor;
	this.history = editor.history;
	this.history.commit();
	this.valid = !!pattern;
	this.atOccurrence = false;
	if (caseFold == undefined) caseFold = typeof pattern == "string" && pattern == pattern.toLowerCase();

	function getText(node){
	  var line = cleanText(editor.history.textAfter(node));
	  return (caseFold ? line.toLowerCase() : line);
	}

	var topPos = {node: null, offset: 0}, self = this;
	if (from && typeof from == "object" && typeof from.character == "number") {
	  editor.checkLine(from.line);
	  var pos = {node: from.line, offset: from.character};
	  this.pos = {from: pos, to: pos};
	}
	else if (from) {
	  this.pos = {from: select.cursorPos(editor.container, true) || topPos,
				  to: select.cursorPos(editor.container, false) || topPos};
	}
	else {
	  this.pos = {from: topPos, to: topPos};
	}

	if (typeof pattern != "string") { // Regexp match
	  this.matches = function(reverse, node, offset) {
		if (reverse) {
		  var line = getText(node).slice(0, offset), match = line.match(pattern), start = 0;
		  while (match) {
			var ind = line.indexOf(match[0]);
			start += ind;
			line = line.slice(ind + 1);
			var newmatch = line.match(pattern);
			if (newmatch) match = newmatch;
			else break;
		  }
		}
		else {
		  var line = getText(node).slice(offset), match = line.match(pattern),
			  start = match && offset + line.indexOf(match[0]);
		}
		if (match) {
		  self.currentMatch = match;
		  return {from: {node: node, offset: start},
				  to: {node: node, offset: start + match[0].length}};
		}
	  };
	  return;
	}

	if (caseFold) pattern = pattern.toLowerCase();
	// Create a matcher function based on the kind of string we have.
	var target = pattern.split("\n");
	this.matches = (target.length == 1) ?
	  // For one-line strings, searching can be done simply by calling
	  // indexOf or lastIndexOf on the current line.
	  function(reverse, node, offset) {
		var line = getText(node), len = pattern.length, match;
		if (reverse ? (offset >= len && (match = line.lastIndexOf(pattern, offset - len)) != -1)
					: (match = line.indexOf(pattern, offset)) != -1)
		  return {from: {node: node, offset: match},
				  to: {node: node, offset: match + len}};
	  } :
	  // Multi-line strings require internal iteration over lines, and
	  // some clunky checks to make sure the first match ends at the
	  // end of the line and the last match starts at the start.
	  function(reverse, node, offset) {
		var idx = (reverse ? target.length - 1 : 0), match = target[idx], line = getText(node);
		var offsetA = (reverse ? line.indexOf(match) + match.length : line.lastIndexOf(match));
		if (reverse ? offsetA >= offset || offsetA != match.length
					: offsetA <= offset || offsetA != line.length - match.length)
		  return;

		var pos = node;
		while (true) {
		  if (reverse && !pos) return;
		  pos = (reverse ? this.history.nodeBefore(pos) : this.history.nodeAfter(pos) );
		  if (!reverse && !pos) return;

		  line = getText(pos);
		  match = target[reverse ? --idx : ++idx];

		  if (idx > 0 && idx < target.length - 1) {
			if (line != match) return;
			else continue;
		  }
		  var offsetB = (reverse ? line.lastIndexOf(match) : line.indexOf(match) + match.length);
		  if (reverse ? offsetB != line.length - match.length : offsetB != match.length)
			return;
		  return {from: {node: reverse ? pos : node, offset: reverse ? offsetB : offsetA},
				  to: {node: reverse ? node : pos, offset: reverse ? offsetA : offsetB}};
		}
	  };
  }

  SearchCursor.prototype = {
	findNext: function() {return this.find(false);},
	findPrevious: function() {return this.find(true);},

	find: function(reverse) {
	  if (!this.valid) return false;

	  var self = this, pos = reverse ? this.pos.from : this.pos.to,
		  node = pos.node, offset = pos.offset;
	  // Reset the cursor if the current line is no longer in the DOM tree.
	  if (node && !node.parentNode) {
		node = null; offset = 0;
	  }
	  function savePosAndFail() {
		var pos = {node: node, offset: offset};
		self.pos = {from: pos, to: pos};
		self.atOccurrence = false;
		return false;
	  }

	  while (true) {
		if (this.pos = this.matches(reverse, node, offset)) {
		  this.atOccurrence = true;
		  return true;
		}

		if (reverse) {
		  if (!node) return savePosAndFail();
		  node = this.history.nodeBefore(node);
		  offset = this.history.textAfter(node).length;
		}
		else {
		  var next = this.history.nodeAfter(node);
		  if (!next) {
			offset = this.history.textAfter(node).length;
			return savePosAndFail();
		  }
		  node = next;
		  offset = 0;
		}
	  }
	},

	select: function() {
	  if (this.atOccurrence) {
		select.setCursorPos(this.editor.container, this.pos.from, this.pos.to);
		select.scrollToCursor(this.editor.container);
	  }
	},

	replace: function(string) {
	  if (this.atOccurrence) {
		var fragments = this.currentMatch;
		if (fragments)
		  string = string.replace(/\\(\d)/, function(m, i){return fragments[i];});
		var end = this.editor.replaceRange(this.pos.from, this.pos.to, string);
		this.pos.to = end;
		this.atOccurrence = false;
	  }
	},

	position: function() {
	  if (this.atOccurrence)
		return {line: this.pos.from.node, character: this.pos.from.offset};
	}
  };

  // The Editor object is the main inside-the-iframe interface.
  function Editor(options) {
	this.options = options;
	window.indentUnit = options.indentUnit;
	var container = this.container = document.body;
	this.history = new UndoHistory(container, options.undoDepth, options.undoDelay, this);
	var self = this;

	if (!Editor.Parser)
	  throw "No parser loaded.";
	if (options.parserConfig && Editor.Parser.configure)
	  Editor.Parser.configure(options.parserConfig);

	if (!options.readOnly && !internetExplorer)
	  select.setCursorPos(container, {node: null, offset: 0});

	this.dirty = [];
	this.importCode(options.content || "");
	this.history.onChange = options.onChange;

	if (!options.readOnly) {
	  if (options.continuousScanning !== false) {
		this.scanner = this.documentScanner(options.passTime);
		this.delayScanning();
	  }

	  function setEditable() {
		// Use contentEditable instead of designMode on IE, since designMode frames
		// can not run any scripts. It would be nice if we could use contentEditable
		// everywhere, but it is significantly flakier than designMode on every
		// single non-IE browser.
		if (document.body.contentEditable != undefined && internetExplorer)
		  document.body.contentEditable = "true";
		else
		  document.designMode = "on";

		// Work around issue where you have to click on the actual
		// body of the document to focus it in IE, making focusing
		// hard when the document is small.
		if (internetExplorer && options.height != "dynamic")
		  document.body.style.minHeight = (
			window.frameElement.clientHeight - 2 * document.body.offsetTop - 5) + "px";

		document.documentElement.style.borderWidth = "0";
		if (!options.textWrapping)
		  container.style.whiteSpace = "nowrap";
	  }

	  // If setting the frame editable fails, try again when the user
	  // focus it (happens when the frame is not visible on
	  // initialisation, in Firefox).
	  try {
		setEditable();
	  }
	  catch(e) {
		var focusEvent = addEventHandler(document, "focus", function() {
		  focusEvent();
		  setEditable();
		}, true);
	  }

	  addEventHandler(document, "keydown", method(this, "keyDown"));
	  addEventHandler(document, "keypress", method(this, "keyPress"));
	  addEventHandler(document, "keyup", method(this, "keyUp"));

	  function cursorActivity() {self.cursorActivity(false);}
	  addEventHandler(internetExplorer ? document.body : window, "mouseup", cursorActivity);
	  addEventHandler(document.body, "cut", cursorActivity);

	  // workaround for a gecko bug [?] where going forward and then
	  // back again breaks designmode (no more cursor)
	  if (gecko)
		addEventHandler(window, "pagehide", function(){self.unloaded = true;});

	  addEventHandler(document.body, "paste", function(event) {
		cursorActivity();
		var text = null;
		try {
		  var clipboardData = event.clipboardData || window.clipboardData;
		  if (clipboardData) text = clipboardData.getData('Text');
		}
		catch(e) {}
		if (text !== null) {
		  event.stop();
		  self.replaceSelection(text);
		  select.scrollToCursor(self.container);
		}
	  });

	  if (this.options.autoMatchParens)
		addEventHandler(document.body, "click", method(this, "scheduleParenHighlight"));
	}
	else if (!options.textWrapping) {
	  container.style.whiteSpace = "nowrap";
	}
  }

  function isSafeKey(code) {
	return (code >= 16 && code <= 18) || // shift, control, alt
		   (code >= 33 && code <= 40); // arrows, home, end
  }

  Editor.prototype = {
	// Import a piece of code into the editor.
	importCode: function(code) {
	  var lines = asEditorLines(code), chunk = 1000;
	  if (!this.options.incrementalLoading || lines.length < chunk) {
		this.history.push(null, null, lines);
		this.history.reset();
	  }
	  else {
		var cur = 0, self = this;
		function addChunk() {
		  var chunklines = lines.slice(cur, cur + chunk);
		  chunklines.push("");
		  self.history.push(self.history.nodeBefore(null), null, chunklines);
		  self.history.reset();
		  cur += chunk;
		  if (cur < lines.length)
			parent.setTimeout(addChunk, 1000);
		}
		addChunk();
	  }
	},

	// Extract the code from the editor.
	getCode: function() {
	  if (!this.container.firstChild)
		return "";

	  var accum = [];
	  select.markSelection();
	  forEach(traverseDOM(this.container.firstChild), method(accum, "push"));
	  select.selectMarked();
	  // On webkit, don't count last (empty) line if the webkitLastLineHack BR is present
	  if (webkit && this.container.lastChild.hackBR)
		accum.pop();
	  webkitLastLineHack(this.container);
	  return cleanText(accum.join(""));
	},

	checkLine: function(node) {
	  if (node === false || !(node == null || node.parentNode == this.container || node.hackBR))
		throw parent.CodeMirror.InvalidLineHandle;
	},

	cursorPosition: function(start) {
	  if (start == null) start = true;
	  var pos = select.cursorPos(this.container, start);
	  if (pos) return {line: pos.node, character: pos.offset};
	  else return {line: null, character: 0};
	},

	firstLine: function() {
	  return null;
	},

	lastLine: function() {
	  var last = this.container.lastChild;
	  if (last) last = startOfLine(last);
	  if (last && last.hackBR) last = startOfLine(last.previousSibling);
	  return last;
	},

	nextLine: function(line) {
	  this.checkLine(line);
	  var end = endOfLine(line, this.container);
	  if (!end || end.hackBR) return false;
	  else return end;
	},

	prevLine: function(line) {
	  this.checkLine(line);
	  if (line == null) return false;
	  return startOfLine(line.previousSibling);
	},

	visibleLineCount: function() {
	  var line = this.container.firstChild;
	  while (line && isBR(line)) line = line.nextSibling; // BR heights are unreliable
	  if (!line) return false;
	  var innerHeight = (window.innerHeight
						 || document.documentElement.clientHeight
						 || document.body.clientHeight);
	  return Math.floor(innerHeight / line.offsetHeight);
	},

	selectLines: function(startLine, startOffset, endLine, endOffset) {
	  this.checkLine(startLine);
	  var start = {node: startLine, offset: startOffset}, end = null;
	  if (endOffset !== undefined) {
		this.checkLine(endLine);
		end = {node: endLine, offset: endOffset};
	  }
	  select.setCursorPos(this.container, start, end);
	  select.scrollToCursor(this.container);
	},

	lineContent: function(line) {
	  var accum = [];
	  for (line = line ? line.nextSibling : this.container.firstChild;
		   line && !isBR(line); line = line.nextSibling)
		accum.push(nodeText(line));
	  return cleanText(accum.join(""));
	},

	setLineContent: function(line, content) {
	  this.history.commit();
	  this.replaceRange({node: line, offset: 0},
						{node: line, offset: this.history.textAfter(line).length},
						content);
	  this.addDirtyNode(line);
	  this.scheduleHighlight();
	},

	removeLine: function(line) {
	  var node = line ? line.nextSibling : this.container.firstChild;
	  while (node) {
		var next = node.nextSibling;
		removeElement(node);
		if (isBR(node)) break;
		node = next;
	  }
	  this.addDirtyNode(line);
	  this.scheduleHighlight();
	},

	insertIntoLine: function(line, position, content) {
	  var before = null;
	  if (position == "end") {
		before = endOfLine(line, this.container);
	  }
	  else {
		for (var cur = line ? line.nextSibling : this.container.firstChild; cur; cur = cur.nextSibling) {
		  if (position == 0) {
			before = cur;
			break;
		  }
		  var text = nodeText(cur);
		  if (text.length > position) {
			before = cur.nextSibling;
			content = text.slice(0, position) + content + text.slice(position);
			removeElement(cur);
			break;
		  }
		  position -= text.length;
		}
	  }

	  var lines = asEditorLines(content);
	  for (var i = 0; i < lines.length; i++) {
		if (i > 0) this.container.insertBefore(document.createElement("BR"), before);
		this.container.insertBefore(makePartSpan(lines[i]), before);
	  }
	  this.addDirtyNode(line);
	  this.scheduleHighlight();
	},

	// Retrieve the selected text.
	selectedText: function() {
	  var h = this.history;
	  h.commit();

	  var start = select.cursorPos(this.container, true),
		  end = select.cursorPos(this.container, false);
	  if (!start || !end) return "";

	  if (start.node == end.node)
		return h.textAfter(start.node).slice(start.offset, end.offset);

	  var text = [h.textAfter(start.node).slice(start.offset)];
	  for (var pos = h.nodeAfter(start.node); pos != end.node; pos = h.nodeAfter(pos))
		text.push(h.textAfter(pos));
	  text.push(h.textAfter(end.node).slice(0, end.offset));
	  return cleanText(text.join("\n"));
	},

	// Replace the selection with another piece of text.
	replaceSelection: function(text) {
	  this.history.commit();

	  var start = select.cursorPos(this.container, true),
		  end = select.cursorPos(this.container, false);
	  if (!start || !end) return;

	  end = this.replaceRange(start, end, text);
	  select.setCursorPos(this.container, end);
	  webkitLastLineHack(this.container);
	},

	cursorCoords: function(start, internal) {
	  var sel = select.cursorPos(this.container, start);
	  if (!sel) return null;
	  var off = sel.offset, node = sel.node, self = this;
	  function measureFromNode(node, xOffset) {
		var y = -(document.body.scrollTop || document.documentElement.scrollTop || 0),
			x = -(document.body.scrollLeft || document.documentElement.scrollLeft || 0) + xOffset;
		forEach([node, internal ? null : window.frameElement], function(n) {
		  while (n) {x += n.offsetLeft; y += n.offsetTop;n = n.offsetParent;}
		});
		return {x: x, y: y, yBot: y + node.offsetHeight};
	  }
	  function withTempNode(text, f) {
		var node = document.createElement("SPAN");
		node.appendChild(document.createTextNode(text));
		try {return f(node);}
		finally {if (node.parentNode) node.parentNode.removeChild(node);}
	  }

	  while (off) {
		node = node ? node.nextSibling : this.container.firstChild;
		var txt = nodeText(node);
		if (off < txt.length)
		  return withTempNode(txt.substr(0, off), function(tmp) {
			tmp.style.position = "absolute"; tmp.style.visibility = "hidden";
			tmp.className = node.className;
			self.container.appendChild(tmp);
			return measureFromNode(node, tmp.offsetWidth);
		  });
		off -= txt.length;
	  }
	  if (node && isSpan(node))
		return measureFromNode(node, node.offsetWidth);
	  else if (node && node.nextSibling && isSpan(node.nextSibling))
		return measureFromNode(node.nextSibling, 0);
	  else
		return withTempNode("\u200b", function(tmp) {
		  if (node) node.parentNode.insertBefore(tmp, node.nextSibling);
		  else self.container.insertBefore(tmp, self.container.firstChild);
		  return measureFromNode(tmp, 0);
		});
	},

	reroutePasteEvent: function() {
	  if (this.capturingPaste || window.opera || (gecko && gecko >= 20101026)) return;
	  this.capturingPaste = true;
	  var te = window.frameElement.CodeMirror.textareaHack;
	  var coords = this.cursorCoords(true, true);
	  te.style.top = coords.y + "px";
	  if (internetExplorer) {
		var snapshot = select.getBookmark(this.container);
		if (snapshot) this.selectionSnapshot = snapshot;
	  }
	  parent.focus();
	  te.value = "";
	  te.focus();

	  var self = this;
	  parent.setTimeout(function() {
		self.capturingPaste = false;
		window.focus();
		if (self.selectionSnapshot) // IE hack
		  window.select.setBookmark(self.container, self.selectionSnapshot);
		var text = te.value;
		if (text) {
		  self.replaceSelection(text);
		  select.scrollToCursor(self.container);
		}
	  }, 10);
	},

	replaceRange: function(from, to, text) {
	  var lines = asEditorLines(text);
	  lines[0] = this.history.textAfter(from.node).slice(0, from.offset) + lines[0];
	  var lastLine = lines[lines.length - 1];
	  lines[lines.length - 1] = lastLine + this.history.textAfter(to.node).slice(to.offset);
	  var end = this.history.nodeAfter(to.node);
	  this.history.push(from.node, end, lines);
	  return {node: this.history.nodeBefore(end),
			  offset: lastLine.length};
	},

	getSearchCursor: function(string, fromCursor, caseFold) {
	  return new SearchCursor(this, string, fromCursor, caseFold);
	},

	// Re-indent the whole buffer
	reindent: function() {
	  if (this.container.firstChild)
		this.indentRegion(null, this.container.lastChild);
	},

	reindentSelection: function(direction) {
	  if (!select.somethingSelected()) {
		this.indentAtCursor(direction);
	  }
	  else {
		var start = select.selectionTopNode(this.container, true),
			end = select.selectionTopNode(this.container, false);
		if (start === false || end === false) return;
		this.indentRegion(start, end, direction, true);
	  }
	},

	grabKeys: function(eventHandler, filter) {
	  this.frozen = eventHandler;
	  this.keyFilter = filter;
	},
	ungrabKeys: function() {
	  this.frozen = "leave";
	},

	setParser: function(name, parserConfig) {
	  Editor.Parser = window[name];
	  parserConfig = parserConfig || this.options.parserConfig;
	  if (parserConfig && Editor.Parser.configure)
		Editor.Parser.configure(parserConfig);

	  if (this.container.firstChild) {
		forEach(this.container.childNodes, function(n) {
		  if (n.nodeType != 3) n.dirty = true;
		});
		this.addDirtyNode(this.firstChild);
		this.scheduleHighlight();
	  }
	},

	// Intercept enter and tab, and assign their new functions.
	keyDown: function(event) {
	  if (this.frozen == "leave") {this.frozen = null; this.keyFilter = null;}
	  if (this.frozen && (!this.keyFilter || this.keyFilter(event.keyCode, event))) {
		event.stop();
		this.frozen(event);
		return;
	  }

	  var code = event.keyCode;
	  // Don't scan when the user is typing.
	  this.delayScanning();
	  // Schedule a paren-highlight event, if configured.
	  if (this.options.autoMatchParens)
		this.scheduleParenHighlight();

	  // The various checks for !altKey are there because AltGr sets both
	  // ctrlKey and altKey to true, and should not be recognised as
	  // Control.
	  if (code == 13) { // enter
		if (event.ctrlKey && !event.altKey) {
		  this.reparseBuffer();
		}
		else {
		  select.insertNewlineAtCursor();
		  var mode = this.options.enterMode;
		  if (mode != "flat") this.indentAtCursor(mode == "keep" ? "keep" : undefined);
		  select.scrollToCursor(this.container);
		}
		event.stop();
	  }
	  else if (code == 9 && this.options.tabMode != "default" && !event.ctrlKey) { // tab
		this.handleTab(!event.shiftKey);
		event.stop();
	  }
	  else if (code == 32 && event.shiftKey && this.options.tabMode == "default") { // space
		this.handleTab(true);
		event.stop();
	  }
	  else if (code == 36 && !event.shiftKey && !event.ctrlKey) { // home
		if (this.home()) event.stop();
	  }
	  else if (code == 35 && !event.shiftKey && !event.ctrlKey) { // end
		if (this.end()) event.stop();
	  }
	  // Only in Firefox is the default behavior for PgUp/PgDn correct.
	  else if (code == 33 && !event.shiftKey && !event.ctrlKey && !gecko) { // PgUp
		if (this.pageUp()) event.stop();
	  }
	  else if (code == 34 && !event.shiftKey && !event.ctrlKey && !gecko) {  // PgDn
		if (this.pageDown()) event.stop();
	  }
	  else if ((code == 219 || code == 221) && event.ctrlKey && !event.altKey) { // [, ]
		this.highlightParens(event.shiftKey, true);
		event.stop();
	  }
	  else if (event.metaKey && !event.shiftKey && (code == 37 || code == 39)) { // Meta-left/right
		var cursor = select.selectionTopNode(this.container);
		if (cursor === false || !this.container.firstChild) return;

		if (code == 37) select.focusAfterNode(startOfLine(cursor), this.container);
		else {
		  var end = endOfLine(cursor, this.container);
		  select.focusAfterNode(end ? end.previousSibling : this.container.lastChild, this.container);
		}
		event.stop();
	  }
	  else if ((event.ctrlKey || event.metaKey) && !event.altKey) {
		if ((event.shiftKey && code == 90) || code == 89) { // shift-Z, Y
		  select.scrollToNode(this.history.redo());
		  event.stop();
		}
		else if (code == 90 || (safari && code == 8)) { // Z, backspace
		  select.scrollToNode(this.history.undo());
		  event.stop();
		}
		else if (code == 83 && this.options.saveFunction) { // S
		  this.options.saveFunction();
		  event.stop();
		}
		else if (code == 86 && !mac) { // V
		  this.reroutePasteEvent();
		}
	  }
	},

	// Check for characters that should re-indent the current line,
	// and prevent Opera from handling enter and tab anyway.
	keyPress: function(event) {
	  var electric = this.options.electricChars && Editor.Parser.electricChars, self = this;
	  // Hack for Opera, and Firefox on OS X, in which stopping a
	  // keydown event does not prevent the associated keypress event
	  // from happening, so we have to cancel enter and tab again
	  // here.
	  if ((this.frozen && (!this.keyFilter || this.keyFilter(event.keyCode || event.code, event))) ||
		  event.code == 13 || (event.code == 9 && this.options.tabMode != "default") ||
		  (event.code == 32 && event.shiftKey && this.options.tabMode == "default"))
		event.stop();
	  else if (mac && (event.ctrlKey || event.metaKey) && event.character == "v") {
		this.reroutePasteEvent();
	  }
	  else if (electric && electric.indexOf(event.character) != -1)
		parent.setTimeout(function(){self.indentAtCursor(null);}, 0);
	  // Work around a bug where pressing backspace at the end of a
	  // line, or delete at the start, often causes the cursor to jump
	  // to the start of the line in Opera 10.60.
	  else if (brokenOpera) {
		if (event.code == 8) { // backspace
		  var sel = select.selectionTopNode(this.container), self = this,
			  next = sel ? sel.nextSibling : this.container.firstChild;
		  if (sel !== false && next && isBR(next))
			parent.setTimeout(function(){
			  if (select.selectionTopNode(self.container) == next)
				select.focusAfterNode(next.previousSibling, self.container);
			}, 20);
		}
		else if (event.code == 46) { // delete
		  var sel = select.selectionTopNode(this.container), self = this;
		  if (sel && isBR(sel)) {
			parent.setTimeout(function(){
			  if (select.selectionTopNode(self.container) != sel)
				select.focusAfterNode(sel, self.container);
			}, 20);
		  }
		}
	  }
	  // In 533.* WebKit versions, when the document is big, typing
	  // something at the end of a line causes the browser to do some
	  // kind of stupid heavy operation, creating delays of several
	  // seconds before the typed characters appear. This very crude
	  // hack inserts a temporary zero-width space after the cursor to
	  // make it not be at the end of the line.
	  else if (slowWebkit) {
		var sel = select.selectionTopNode(this.container),
			next = sel ? sel.nextSibling : this.container.firstChild;
		// Doesn't work on empty lines, for some reason those always
		// trigger the delay.
		if (sel && next && isBR(next) && !isBR(sel)) {
		  var cheat = document.createTextNode("\u200b");
		  this.container.insertBefore(cheat, next);
		  parent.setTimeout(function() {
			if (cheat.nodeValue == "\u200b") removeElement(cheat);
			else cheat.nodeValue = cheat.nodeValue.replace("\u200b", "");
		  }, 20);
		}
	  }

	  // Magic incantation that works abound a webkit bug when you
	  // can't type on a blank line following a line that's wider than
	  // the window.
	  if (webkit && !this.options.textWrapping)
		setTimeout(function () {
		  var node = select.selectionTopNode(self.container, true);
		  if (node && node.nodeType == 3 && node.previousSibling && isBR(node.previousSibling)
			  && node.nextSibling && isBR(node.nextSibling))
			node.parentNode.replaceChild(document.createElement("BR"), node.previousSibling);
		}, 50);
	},

	// Mark the node at the cursor dirty when a non-safe key is
	// released.
	keyUp: function(event) {
	  this.cursorActivity(isSafeKey(event.keyCode));
	},

	// Indent the line following a given <br>, or null for the first
	// line. If given a <br> element, this must have been highlighted
	// so that it has an indentation method. Returns the whitespace
	// element that has been modified or created (if any).
	indentLineAfter: function(start, direction) {
	  function whiteSpaceAfter(node) {
		var ws = node ? node.nextSibling : self.container.firstChild;
		if (!ws || !hasClass(ws, "whitespace")) return null;
		return ws;
	  }

	  // whiteSpace is the whitespace span at the start of the line,
	  // or null if there is no such node.
	  var self = this, whiteSpace = whiteSpaceAfter(start);
	  var newIndent = 0, curIndent = whiteSpace ? whiteSpace.currentText.length : 0;

	  var firstText = whiteSpace ? whiteSpace.nextSibling : (start ? start.nextSibling : this.container.firstChild);
	  if (direction == "keep") {
		if (start) {
		  var prevWS = whiteSpaceAfter(startOfLine(start.previousSibling))
		  if (prevWS) newIndent = prevWS.currentText.length;
		}
	  }
	  else {
		// Sometimes the start of the line can influence the correct
		// indentation, so we retrieve it.
		var nextChars = (start && firstText && firstText.currentText) ? firstText.currentText : "";

		// Ask the lexical context for the correct indentation, and
		// compute how much this differs from the current indentation.
		if (direction != null && this.options.tabMode != "indent")
		  newIndent = direction ? curIndent + indentUnit : Math.max(0, curIndent - indentUnit)
		else if (start)
		  newIndent = start.indentation(nextChars, curIndent, direction, firstText);
		else if (Editor.Parser.firstIndentation)
		  newIndent = Editor.Parser.firstIndentation(nextChars, curIndent, direction, firstText);
	  }

	  var indentDiff = newIndent - curIndent;

	  // If there is too much, this is just a matter of shrinking a span.
	  if (indentDiff < 0) {
		if (newIndent == 0) {
		  if (firstText) select.snapshotMove(whiteSpace.firstChild, firstText.firstChild || firstText, 0);
		  removeElement(whiteSpace);
		  whiteSpace = null;
		}
		else {
		  select.snapshotMove(whiteSpace.firstChild, whiteSpace.firstChild, indentDiff, true);
		  whiteSpace.currentText = makeWhiteSpace(newIndent);
		  whiteSpace.firstChild.nodeValue = whiteSpace.currentText;
		}
	  }
	  // Not enough...
	  else if (indentDiff > 0) {
		// If there is whitespace, we grow it.
		if (whiteSpace) {
		  whiteSpace.currentText = makeWhiteSpace(newIndent);
		  whiteSpace.firstChild.nodeValue = whiteSpace.currentText;
		  select.snapshotMove(whiteSpace.firstChild, whiteSpace.firstChild, indentDiff, true);
		}
		// Otherwise, we have to add a new whitespace node.
		else {
		  whiteSpace = makePartSpan(makeWhiteSpace(newIndent));
		  whiteSpace.className = "whitespace";
		  if (start) insertAfter(whiteSpace, start);
		  else this.container.insertBefore(whiteSpace, this.container.firstChild);
		  select.snapshotMove(firstText && (firstText.firstChild || firstText),
							  whiteSpace.firstChild, newIndent, false, true);
		}
	  }
	  // Make sure cursor ends up after the whitespace
	  else if (whiteSpace) {
	select.snapshotMove(whiteSpace.firstChild, whiteSpace.firstChild, newIndent, false);
	  }
	  if (indentDiff != 0) this.addDirtyNode(start);
	},

	// Re-highlight the selected part of the document.
	highlightAtCursor: function() {
	  var pos = select.selectionTopNode(this.container, true);
	  var to = select.selectionTopNode(this.container, false);
	  if (pos === false || to === false) return false;

	  select.markSelection();
	  if (this.highlight(pos, endOfLine(to, this.container), true, 20) === false)
		return false;
	  select.selectMarked();
	  return true;
	},

	// When tab is pressed with text selected, the whole selection is
	// re-indented, when nothing is selected, the line with the cursor
	// is re-indented.
	handleTab: function(direction) {
	  if (this.options.tabMode == "spaces" && !select.somethingSelected())
		select.insertTabAtCursor();
	  else
		this.reindentSelection(direction);
	},

	// Custom home behaviour that doesn't land the cursor in front of
	// leading whitespace unless pressed twice.
	home: function() {
	  var cur = select.selectionTopNode(this.container, true), start = cur;
	  if (cur === false || !(!cur || cur.isPart || isBR(cur)) || !this.container.firstChild)
		return false;

	  while (cur && !isBR(cur)) cur = cur.previousSibling;
	  var next = cur ? cur.nextSibling : this.container.firstChild;
	  if (next && next != start && next.isPart && hasClass(next, "whitespace"))
		select.focusAfterNode(next, this.container);
	  else
		select.focusAfterNode(cur, this.container);

	  select.scrollToCursor(this.container);
	  return true;
	},

	// Some browsers (Opera) don't manage to handle the end key
	// properly in the face of vertical scrolling.
	end: function() {
	  var cur = select.selectionTopNode(this.container, true);
	  if (cur === false) return false;
	  cur = endOfLine(cur, this.container);
	  if (!cur) return false;
	  select.focusAfterNode(cur.previousSibling, this.container);
	  select.scrollToCursor(this.container);
	  return true;
	},

	pageUp: function() {
	  var line = this.cursorPosition().line, scrollAmount = this.visibleLineCount();
	  if (line === false || scrollAmount === false) return false;
	  // Try to keep one line on the screen.
	  scrollAmount -= 2;
	  for (var i = 0; i < scrollAmount; i++) {
		line = this.prevLine(line);
		if (line === false) break;
	  }
	  if (i == 0) return false; // Already at first line
	  select.setCursorPos(this.container, {node: line, offset: 0});
	  select.scrollToCursor(this.container);
	  return true;
	},

	pageDown: function() {
	  var line = this.cursorPosition().line, scrollAmount = this.visibleLineCount();
	  if (line === false || scrollAmount === false) return false;
	  // Try to move to the last line of the current page.
	  scrollAmount -= 2;
	  for (var i = 0; i < scrollAmount; i++) {
		var nextLine = this.nextLine(line);
		if (nextLine === false) break;
		line = nextLine;
	  }
	  if (i == 0) return false; // Already at last line
	  select.setCursorPos(this.container, {node: line, offset: 0});
	  select.scrollToCursor(this.container);
	  return true;
	},

	// Delay (or initiate) the next paren highlight event.
	scheduleParenHighlight: function() {
	  if (this.parenEvent) parent.clearTimeout(this.parenEvent);
	  var self = this;
	  this.parenEvent = parent.setTimeout(function(){self.highlightParens();}, 300);
	},

	// Take the token before the cursor. If it contains a character in
	// '()[]{}', search for the matching paren/brace/bracket, and
	// highlight them in green for a moment, or red if no proper match
	// was found.
	highlightParens: function(jump, fromKey) {
	  var self = this, mark = this.options.markParen;
	  if (typeof mark == "string") mark = [mark, mark];
	  // give the relevant nodes a colour.
	  function highlight(node, ok) {
		if (!node) return;
		if (!mark) {
		  node.style.fontWeight = "bold";
		  node.style.color = ok ? "#8F8" : "#F88";
		}
		else if (mark.call) mark(node, ok);
		else node.className += " " + mark[ok ? 0 : 1];
	  }
	  function unhighlight(node) {
		if (!node) return;
		if (mark && !mark.call)
		  removeClass(removeClass(node, mark[0]), mark[1]);
		else if (self.options.unmarkParen)
		  self.options.unmarkParen(node);
		else {
		  node.style.fontWeight = "";
		  node.style.color = "";
		}
	  }
	  if (!fromKey && self.highlighted) {
		unhighlight(self.highlighted[0]);
		unhighlight(self.highlighted[1]);
	  }

	  if (!window || !window.parent || !window.select) return;
	  // Clear the event property.
	  if (this.parenEvent) parent.clearTimeout(this.parenEvent);
	  this.parenEvent = null;

	  // Extract a 'paren' from a piece of text.
	  function paren(node) {
		if (node.currentText) {
		  var match = node.currentText.match(/^[\s\u00a0]*([\(\)\[\]{}])[\s\u00a0]*$/);
		  return match && match[1];
		}
	  }
	  // Determine the direction a paren is facing.
	  function forward(ch) {
		return /[\(\[\{]/.test(ch);
	  }

	  var ch, cursor = select.selectionTopNode(this.container, true);
	  if (!cursor || !this.highlightAtCursor()) return;
	  cursor = select.selectionTopNode(this.container, true);
	  if (!(cursor && ((ch = paren(cursor)) || (cursor = cursor.nextSibling) && (ch = paren(cursor)))))
		return;
	  // We only look for tokens with the same className.
	  var className = cursor.className, dir = forward(ch), match = matching[ch];

	  // Since parts of the document might not have been properly
	  // highlighted, and it is hard to know in advance which part we
	  // have to scan, we just try, and when we find dirty nodes we
	  // abort, parse them, and re-try.
	  function tryFindMatch() {
		var stack = [], ch, ok = true;
		for (var runner = cursor; runner; runner = dir ? runner.nextSibling : runner.previousSibling) {
		  if (runner.className == className && isSpan(runner) && (ch = paren(runner))) {
			if (forward(ch) == dir)
			  stack.push(ch);
			else if (!stack.length)
			  ok = false;
			else if (stack.pop() != matching[ch])
			  ok = false;
			if (!stack.length) break;
		  }
		  else if (runner.dirty || !isSpan(runner) && !isBR(runner)) {
			return {node: runner, status: "dirty"};
		  }
		}
		return {node: runner, status: runner && ok};
	  }

	  while (true) {
		var found = tryFindMatch();
		if (found.status == "dirty") {
		  this.highlight(found.node, endOfLine(found.node));
		  // Needed because in some corner cases a highlight does not
		  // reach a node.
		  found.node.dirty = false;
		  continue;
		}
		else {
		  highlight(cursor, found.status);
		  highlight(found.node, found.status);
		  if (fromKey)
			parent.setTimeout(function() {unhighlight(cursor); unhighlight(found.node);}, 500);
		  else
			self.highlighted = [cursor, found.node];
		  if (jump && found.node)
			select.focusAfterNode(found.node.previousSibling, this.container);
		  break;
		}
	  }
	},

	// Adjust the amount of whitespace at the start of the line that
	// the cursor is on so that it is indented properly.
	indentAtCursor: function(direction) {
	  if (!this.container.firstChild) return;
	  // The line has to have up-to-date lexical information, so we
	  // highlight it first.
	  if (!this.highlightAtCursor()) return;
	  var cursor = select.selectionTopNode(this.container, false);
	  // If we couldn't determine the place of the cursor,
	  // there's nothing to indent.
	  if (cursor === false)
		return;
	  select.markSelection();
	  this.indentLineAfter(startOfLine(cursor), direction);
	  select.selectMarked();
	},

	// Indent all lines whose start falls inside of the current
	// selection.
	indentRegion: function(start, end, direction, selectAfter) {
	  var current = (start = startOfLine(start)), before = start && startOfLine(start.previousSibling);
	  if (!isBR(end)) end = endOfLine(end, this.container);
	  this.addDirtyNode(start);

	  do {
		var next = endOfLine(current, this.container);
		if (current) this.highlight(before, next, true);
		this.indentLineAfter(current, direction);
		before = current;
		current = next;
	  } while (current != end);
	  if (selectAfter)
		select.setCursorPos(this.container, {node: start, offset: 0}, {node: end, offset: 0});
	},

	// Find the node that the cursor is in, mark it as dirty, and make
	// sure a highlight pass is scheduled.
	cursorActivity: function(safe) {
	  // pagehide event hack above
	  if (this.unloaded) {
		window.document.designMode = "off";
		window.document.designMode = "on";
		this.unloaded = false;
	  }

	  if (internetExplorer) {
		this.container.createTextRange().execCommand("unlink");
		clearTimeout(this.saveSelectionSnapshot);
		var self = this;
		this.saveSelectionSnapshot = setTimeout(function() {
		  var snapshot = select.getBookmark(self.container);
		  if (snapshot) self.selectionSnapshot = snapshot;
		}, 200);
	  }

	  var activity = this.options.onCursorActivity;
	  if (!safe || activity) {
		var cursor = select.selectionTopNode(this.container, false);
		if (cursor === false || !this.container.firstChild) return;
		cursor = cursor || this.container.firstChild;
		if (activity) activity(cursor);
		if (!safe) {
		  this.scheduleHighlight();
		  this.addDirtyNode(cursor);
		}
	  }
	},

	reparseBuffer: function() {
	  forEach(this.container.childNodes, function(node) {node.dirty = true;});
	  if (this.container.firstChild)
		this.addDirtyNode(this.container.firstChild);
	},

	// Add a node to the set of dirty nodes, if it isn't already in
	// there.
	addDirtyNode: function(node) {
	  node = node || this.container.firstChild;
	  if (!node) return;

	  for (var i = 0; i < this.dirty.length; i++)
		if (this.dirty[i] == node) return;

	  if (node.nodeType != 3)
		node.dirty = true;
	  this.dirty.push(node);
	},

	allClean: function() {
	  return !this.dirty.length;
	},

	// Cause a highlight pass to happen in options.passDelay
	// milliseconds. Clear the existing timeout, if one exists. This
	// way, the passes do not happen while the user is typing, and
	// should as unobtrusive as possible.
	scheduleHighlight: function() {
	  // Timeouts are routed through the parent window, because on
	  // some browsers designMode windows do not fire timeouts.
	  var self = this;
	  parent.clearTimeout(this.highlightTimeout);
	  this.highlightTimeout = parent.setTimeout(function(){self.highlightDirty();}, this.options.passDelay);
	},

	// Fetch one dirty node, and remove it from the dirty set.
	getDirtyNode: function() {
	  while (this.dirty.length > 0) {
		var found = this.dirty.pop();
		// IE8 sometimes throws an unexplainable 'invalid argument'
		// exception for found.parentNode
		try {
		  // If the node has been coloured in the meantime, or is no
		  // longer in the document, it should not be returned.
		  while (found && found.parentNode != this.container)
			found = found.parentNode;
		  if (found && (found.dirty || found.nodeType == 3))
			return found;
		} catch (e) {}
	  }
	  return null;
	},

	// Pick dirty nodes, and highlight them, until options.passTime
	// milliseconds have gone by. The highlight method will continue
	// to next lines as long as it finds dirty nodes. It returns
	// information about the place where it stopped. If there are
	// dirty nodes left after this function has spent all its lines,
	// it shedules another highlight to finish the job.
	highlightDirty: function(force) {
	  // Prevent FF from raising an error when it is firing timeouts
	  // on a page that's no longer loaded.
	  if (!window || !window.parent || !window.select) return false;

	  if (!this.options.readOnly) select.markSelection();
	  var start, endTime = force ? null : time() + this.options.passTime;
	  while ((time() < endTime || force) && (start = this.getDirtyNode())) {
		var result = this.highlight(start, endTime);
		if (result && result.node && result.dirty)
		  this.addDirtyNode(result.node.nextSibling);
	  }
	  if (!this.options.readOnly) select.selectMarked();
	  if (start) this.scheduleHighlight();
	  return this.dirty.length == 0;
	},

	// Creates a function that, when called through a timeout, will
	// continuously re-parse the document.
	documentScanner: function(passTime) {
	  var self = this, pos = null;
	  return function() {
		// FF timeout weirdness workaround.
		if (!window || !window.parent || !window.select) return;
		// If the current node is no longer in the document... oh
		// well, we start over.
		if (pos && pos.parentNode != self.container)
		  pos = null;
		select.markSelection();
		var result = self.highlight(pos, time() + passTime, true);
		select.selectMarked();
		var newPos = result ? (result.node && result.node.nextSibling) : null;
		pos = (pos == newPos) ? null : newPos;
		self.delayScanning();
	  };
	},

	// Starts the continuous scanning process for this document after
	// a given interval.
	delayScanning: function() {
	  if (this.scanner) {
		parent.clearTimeout(this.documentScan);
		this.documentScan = parent.setTimeout(this.scanner, this.options.continuousScanning);
	  }
	},

	// The function that does the actual highlighting/colouring (with
	// help from the parser and the DOM normalizer). Its interface is
	// rather overcomplicated, because it is used in different
	// situations: ensuring that a certain line is highlighted, or
	// highlighting up to X milliseconds starting from a certain
	// point. The 'from' argument gives the node at which it should
	// start. If this is null, it will start at the beginning of the
	// document. When a timestamp is given with the 'target' argument,
	// it will stop highlighting at that time. If this argument holds
	// a DOM node, it will highlight until it reaches that node. If at
	// any time it comes across two 'clean' lines (no dirty nodes), it
	// will stop, except when 'cleanLines' is true. maxBacktrack is
	// the maximum number of lines to backtrack to find an existing
	// parser instance. This is used to give up in situations where a
	// highlight would take too long and freeze the browser interface.
	highlight: function(from, target, cleanLines, maxBacktrack){
	  var container = this.container, self = this, active = this.options.activeTokens;
	  var endTime = (typeof target == "number" ? target : null);

	  if (!container.firstChild)
		return false;
	  // Backtrack to the first node before from that has a partial
	  // parse stored.
	  while (from && (!from.parserFromHere || from.dirty)) {
		if (maxBacktrack != null && isBR(from) && (--maxBacktrack) < 0)
		  return false;
		from = from.previousSibling;
	  }
	  // If we are at the end of the document, do nothing.
	  if (from && !from.nextSibling)
		return false;

	  // Check whether a part (<span> node) and the corresponding token
	  // match.
	  function correctPart(token, part){
		return !part.reduced && part.currentText == token.value && part.className == token.style;
	  }
	  // Shorten the text associated with a part by chopping off
	  // characters from the front. Note that only the currentText
	  // property gets changed. For efficiency reasons, we leave the
	  // nodeValue alone -- we set the reduced flag to indicate that
	  // this part must be replaced.
	  function shortenPart(part, minus){
		part.currentText = part.currentText.substring(minus);
		part.reduced = true;
	  }
	  // Create a part corresponding to a given token.
	  function tokenPart(token){
		var part = makePartSpan(token.value);
		part.className = token.style;
		return part;
	  }

	  function maybeTouch(node) {
		if (node) {
		  var old = node.oldNextSibling;
		  if (lineDirty || old === undefined || node.nextSibling != old)
			self.history.touch(node);
		  node.oldNextSibling = node.nextSibling;
		}
		else {
		  var old = self.container.oldFirstChild;
		  if (lineDirty || old === undefined || self.container.firstChild != old)
			self.history.touch(null);
		  self.container.oldFirstChild = self.container.firstChild;
		}
	  }

	  // Get the token stream. If from is null, we start with a new
	  // parser from the start of the frame, otherwise a partial parse
	  // is resumed.
	  var traversal = traverseDOM(from ? from.nextSibling : container.firstChild),
		  stream = stringStream(traversal),
		  parsed = from ? from.parserFromHere(stream) : Editor.Parser.make(stream);

	  function surroundedByBRs(node) {
		return (node.previousSibling == null || isBR(node.previousSibling)) &&
			   (node.nextSibling == null || isBR(node.nextSibling));
	  }

	  // parts is an interface to make it possible to 'delay' fetching
	  // the next DOM node until we are completely done with the one
	  // before it. This is necessary because often the next node is
	  // not yet available when we want to proceed past the current
	  // one.
	  var parts = {
		current: null,
		// Fetch current node.
		get: function(){
		  if (!this.current)
			this.current = traversal.nodes.shift();
		  return this.current;
		},
		// Advance to the next part (do not fetch it yet).
		next: function(){
		  this.current = null;
		},
		// Remove the current part from the DOM tree, and move to the
		// next.
		remove: function(){
		  container.removeChild(this.get());
		  this.current = null;
		},
		// Advance to the next part that is not empty, discarding empty
		// parts.
		getNonEmpty: function(){
		  var part = this.get();
		  // Allow empty nodes when they are alone on a line, needed
		  // for the FF cursor bug workaround (see select.js,
		  // insertNewlineAtCursor).
		  while (part && isSpan(part) && part.currentText == "") {
			// Leave empty nodes that are alone on a line alone in
			// Opera, since that browsers doesn't deal well with
			// having 2 BRs in a row.
			if (window.opera && surroundedByBRs(part)) {
			  this.next();
			  part = this.get();
			}
			else {
			  var old = part;
			  this.remove();
			  part = this.get();
			  // Adjust selection information, if any. See select.js for details.
			  select.snapshotMove(old.firstChild, part && (part.firstChild || part), 0);
			}
		  }

		  return part;
		}
	  };

	  var lineDirty = false, prevLineDirty = true, lineNodes = 0;

	  // This forEach loops over the tokens from the parsed stream, and
	  // at the same time uses the parts object to proceed through the
	  // corresponding DOM nodes.
	  forEach(parsed, function(token){
		var part = parts.getNonEmpty();

		if (token.value == "\n"){
		  // The idea of the two streams actually staying synchronized
		  // is such a long shot that we explicitly check.
		  if (!isBR(part))
			throw "Parser out of sync. Expected BR.";

		  if (part.dirty || !part.indentation) lineDirty = true;
		  maybeTouch(from);
		  from = part;

		  // Every <br> gets a copy of the parser state and a lexical
		  // context assigned to it. The first is used to be able to
		  // later resume parsing from this point, the second is used
		  // for indentation.
		  part.parserFromHere = parsed.copy();
		  part.indentation = token.indentation || alwaysZero;
		  part.dirty = false;

		  // If the target argument wasn't an integer, go at least
		  // until that node.
		  if (endTime == null && part == target) throw StopIteration;

		  // A clean line with more than one node means we are done.
		  // Throwing a StopIteration is the way to break out of a
		  // MochiKit forEach loop.
		  if ((endTime != null && time() >= endTime) || (!lineDirty && !prevLineDirty && lineNodes > 1 && !cleanLines))
			throw StopIteration;
		  prevLineDirty = lineDirty; lineDirty = false; lineNodes = 0;
		  parts.next();
		}
		else {
		  if (!isSpan(part))
			throw "Parser out of sync. Expected SPAN.";
		  if (part.dirty)
			lineDirty = true;
		  lineNodes++;

		  // If the part matches the token, we can leave it alone.
		  if (correctPart(token, part)){
			if (active && part.dirty) active(part, token, self);
			part.dirty = false;
			parts.next();
		  }
		  // Otherwise, we have to fix it.
		  else {
			lineDirty = true;
			// Insert the correct part.
			var newPart = tokenPart(token);
			container.insertBefore(newPart, part);
			if (active) active(newPart, token, self);
			var tokensize = token.value.length;
			var offset = 0;
			// Eat up parts until the text for this token has been
			// removed, adjusting the stored selection info (see
			// select.js) in the process.
			while (tokensize > 0) {
			  part = parts.get();
			  var partsize = part.currentText.length;
			  select.snapshotReplaceNode(part.firstChild, newPart.firstChild, tokensize, offset);
			  if (partsize > tokensize){
				shortenPart(part, tokensize);
				tokensize = 0;
			  }
			  else {
				tokensize -= partsize;
				offset += partsize;
				parts.remove();
			  }
			}
		  }
		}
	  });
	  maybeTouch(from);
	  webkitLastLineHack(this.container);

	  // The function returns some status information that is used by
	  // hightlightDirty to determine whether and where it has to
	  // continue.
	  return {node: parts.getNonEmpty(),
			  dirty: lineDirty};
	}
  };

  return Editor;
})();

addEventHandler(window, "load", function() {
  var CodeMirror = window.frameElement.CodeMirror;
  var e = CodeMirror.editor = new Editor(CodeMirror.options);
  parent.setTimeout(method(CodeMirror, "init"), 0);
});

/* Functionality for finding, storing, and restoring selections
 *
 * This does not provide a generic API, just the minimal functionality
 * required by the CodeMirror system.
 */

// Namespace object.
var select = {};

(function() {
  select.ie_selection = document.selection && document.selection.createRangeCollection;

  // Find the 'top-level' (defined as 'a direct child of the node
  // passed as the top argument') node that the given node is
  // contained in. Return null if the given node is not inside the top
  // node.
  function topLevelNodeAt(node, top) {
	while (node && node.parentNode != top)
	  node = node.parentNode;
	return node;
  }

  // Find the top-level node that contains the node before this one.
  function topLevelNodeBefore(node, top) {
	while (!node.previousSibling && node.parentNode != top)
	  node = node.parentNode;
	return topLevelNodeAt(node.previousSibling, top);
  }

  var fourSpaces = "\u00a0\u00a0\u00a0\u00a0";

  select.scrollToNode = function(node, cursor) {
	if (!node) return;
	var element = node, body = document.body,
		html = document.documentElement,
		atEnd = !element.nextSibling || !element.nextSibling.nextSibling
				|| !element.nextSibling.nextSibling.nextSibling;
	// In Opera (and recent Webkit versions), BR elements *always*
	// have a offsetTop property of zero.
	var compensateHack = 0;
	while (element && !element.offsetTop) {
	  compensateHack++;
	  element = element.previousSibling;
	}
	// atEnd is another kludge for these browsers -- if the cursor is
	// at the end of the document, and the node doesn't have an
	// offset, just scroll to the end.
	if (compensateHack == 0) atEnd = false;

	// WebKit has a bad habit of (sometimes) happily returning bogus
	// offsets when the document has just been changed. This seems to
	// always be 5/5, so we don't use those.
	if (webkit && element && element.offsetTop == 5 && element.offsetLeft == 5)
	  return;

	var y = compensateHack * (element ? element.offsetHeight : 0), x = 0,
		width = (node ? node.offsetWidth : 0), pos = element;
	while (pos && pos.offsetParent) {
	  y += pos.offsetTop;
	  // Don't count X offset for <br> nodes
	  if (!isBR(pos))
		x += pos.offsetLeft;
	  pos = pos.offsetParent;
	}

	var scroll_x = body.scrollLeft || html.scrollLeft || 0,
		scroll_y = body.scrollTop || html.scrollTop || 0,
		scroll = false, screen_width = window.innerWidth || html.clientWidth || 0;

	if (cursor || width < screen_width) {
	  if (cursor) {
		var off = select.offsetInNode(node), size = nodeText(node).length;
		if (size) x += width * (off / size);
	  }
	  var screen_x = x - scroll_x;
	  if (screen_x < 0 || screen_x > screen_width) {
		scroll_x = x;
		scroll = true;
	  }
	}
	var screen_y = y - scroll_y;
	if (screen_y < 0 || atEnd || screen_y > (window.innerHeight || html.clientHeight || 0) - 50) {
	  scroll_y = atEnd ? 1e6 : y;
	  scroll = true;
	}
	if (scroll) window.scrollTo(scroll_x, scroll_y);
  };

  select.scrollToCursor = function(container) {
	select.scrollToNode(select.selectionTopNode(container, true) || container.firstChild, true);
  };

  // Used to prevent restoring a selection when we do not need to.
  var currentSelection = null;

  select.snapshotChanged = function() {
	if (currentSelection) currentSelection.changed = true;
  };

  // Find the 'leaf' node (BR or text) after the given one.
  function baseNodeAfter(node) {
	var next = node.nextSibling;
	if (next) {
	  while (next.firstChild) next = next.firstChild;
	  if (next.nodeType == 3 || isBR(next)) return next;
	  else return baseNodeAfter(next);
	}
	else {
	  var parent = node.parentNode;
	  while (parent && !parent.nextSibling) parent = parent.parentNode;
	  return parent && baseNodeAfter(parent);
	}
  }

  // This is called by the code in editor.js whenever it is replacing
  // a text node. The function sees whether the given oldNode is part
  // of the current selection, and updates this selection if it is.
  // Because nodes are often only partially replaced, the length of
  // the part that gets replaced has to be taken into account -- the
  // selection might stay in the oldNode if the newNode is smaller
  // than the selection's offset. The offset argument is needed in
  // case the selection does move to the new object, and the given
  // length is not the whole length of the new node (part of it might
  // have been used to replace another node).
  select.snapshotReplaceNode = function(from, to, length, offset) {
	if (!currentSelection) return;

	function replace(point) {
	  if (from == point.node) {
		currentSelection.changed = true;
		if (length && point.offset > length) {
		  point.offset -= length;
		}
		else {
		  point.node = to;
		  point.offset += (offset || 0);
		}
	  }
	  else if (select.ie_selection && point.offset == 0 && point.node == baseNodeAfter(from)) {
		currentSelection.changed = true;
	  }
	}
	replace(currentSelection.start);
	replace(currentSelection.end);
  };

  select.snapshotMove = function(from, to, distance, relative, ifAtStart) {
	if (!currentSelection) return;

	function move(point) {
	  if (from == point.node && (!ifAtStart || point.offset == 0)) {
		currentSelection.changed = true;
		point.node = to;
		if (relative) point.offset = Math.max(0, point.offset + distance);
		else point.offset = distance;
	  }
	}
	move(currentSelection.start);
	move(currentSelection.end);
  };

  // Most functions are defined in two ways, one for the IE selection
  // model, one for the W3C one.
  if (select.ie_selection) {
	function selRange() {
	  var sel = document.selection;
	  if (!sel) return null;
	  if (sel.createRange) return sel.createRange();
	  else return sel.createTextRange();
	}

	function selectionNode(start) {
	  var range = selRange();
	  range.collapse(start);

	  function nodeAfter(node) {
		var found = null;
		while (!found && node) {
		  found = node.nextSibling;
		  node = node.parentNode;
		}
		return nodeAtStartOf(found);
	  }

	  function nodeAtStartOf(node) {
		while (node && node.firstChild) node = node.firstChild;
		return {node: node, offset: 0};
	  }

	  var containing = range.parentElement();
	  if (!isAncestor(document.body, containing)) return null;
	  if (!containing.firstChild) return nodeAtStartOf(containing);

	  var working = range.duplicate();
	  working.moveToElementText(containing);
	  working.collapse(true);
	  for (var cur = containing.firstChild; cur; cur = cur.nextSibling) {
		if (cur.nodeType == 3) {
		  var size = cur.nodeValue.length;
		  working.move("character", size);
		}
		else {
		  working.moveToElementText(cur);
		  working.collapse(false);
		}

		var dir = range.compareEndPoints("StartToStart", working);
		if (dir == 0) return nodeAfter(cur);
		if (dir == 1) continue;
		if (cur.nodeType != 3) return nodeAtStartOf(cur);

		working.setEndPoint("StartToEnd", range);
		return {node: cur, offset: size - working.text.length};
	  }
	  return nodeAfter(containing);
	}

	select.markSelection = function() {
	  currentSelection = null;
	  var sel = document.selection;
	  if (!sel) return;
	  var start = selectionNode(true),
		  end = selectionNode(false);
	  if (!start || !end) return;
	  currentSelection = {start: start, end: end, changed: false};
	};

	select.selectMarked = function() {
	  if (!currentSelection || !currentSelection.changed) return;

	  function makeRange(point) {
		var range = document.body.createTextRange(),
			node = point.node;
		if (!node) {
		  range.moveToElementText(document.body);
		  range.collapse(false);
		}
		else if (node.nodeType == 3) {
		  range.moveToElementText(node.parentNode);
		  var offset = point.offset;
		  while (node.previousSibling) {
			node = node.previousSibling;
			offset += (node.innerText || "").length;
		  }
		  range.move("character", offset);
		}
		else {
		  range.moveToElementText(node);
		  range.collapse(true);
		}
		return range;
	  }

	  var start = makeRange(currentSelection.start), end = makeRange(currentSelection.end);
	  start.setEndPoint("StartToEnd", end);
	  start.select();
	};

	select.offsetInNode = function(node) {
	  var range = selRange();
	  if (!range) return 0;
	  var range2 = range.duplicate();
	  try {range2.moveToElementText(node);} catch(e){return 0;}
	  range.setEndPoint("StartToStart", range2);
	  return range.text.length;
	};

	// Get the top-level node that one end of the cursor is inside or
	// after. Note that this returns false for 'no cursor', and null
	// for 'start of document'.
	select.selectionTopNode = function(container, start) {
	  var range = selRange();
	  if (!range) return false;
	  var range2 = range.duplicate();
	  range.collapse(start);
	  var around = range.parentElement();
	  if (around && isAncestor(container, around)) {
		// Only use this node if the selection is not at its start.
		range2.moveToElementText(around);
		if (range.compareEndPoints("StartToStart", range2) == 1)
		  return topLevelNodeAt(around, container);
	  }

	  // Move the start of a range to the start of a node,
	  // compensating for the fact that you can't call
	  // moveToElementText with text nodes.
	  function moveToNodeStart(range, node) {
		if (node.nodeType == 3) {
		  var count = 0, cur = node.previousSibling;
		  while (cur && cur.nodeType == 3) {
			count += cur.nodeValue.length;
			cur = cur.previousSibling;
		  }
		  if (cur) {
			try{range.moveToElementText(cur);}
			catch(e){return false;}
			range.collapse(false);
		  }
		  else range.moveToElementText(node.parentNode);
		  if (count) range.move("character", count);
		}
		else {
		  try{range.moveToElementText(node);}
		  catch(e){return false;}
		}
		return true;
	  }

	  // Do a binary search through the container object, comparing
	  // the start of each node to the selection
	  var start = 0, end = container.childNodes.length - 1;
	  while (start < end) {
		var middle = Math.ceil((end + start) / 2), node = container.childNodes[middle];
		if (!node) return false; // Don't ask. IE6 manages this sometimes.
		if (!moveToNodeStart(range2, node)) return false;
		if (range.compareEndPoints("StartToStart", range2) == 1)
		  start = middle;
		else
		  end = middle - 1;
	  }

	  if (start == 0) {
		var test1 = selRange(), test2 = test1.duplicate();
		try {
		  test2.moveToElementText(container);
		} catch(exception) {
		  return null;
		}
		if (test1.compareEndPoints("StartToStart", test2) == 0)
		  return null;
	  }
	  return container.childNodes[start] || null;
	};

	// Place the cursor after this.start. This is only useful when
	// manually moving the cursor instead of restoring it to its old
	// position.
	select.focusAfterNode = function(node, container) {
	  var range = document.body.createTextRange();
	  range.moveToElementText(node || container);
	  range.collapse(!node);
	  range.select();
	};

	select.somethingSelected = function() {
	  var range = selRange();
	  return range && (range.text != "");
	};

	function insertAtCursor(html) {
	  var range = selRange();
	  if (range) {
		range.pasteHTML(html);
		range.collapse(false);
		range.select();
	  }
	}

	// Used to normalize the effect of the enter key, since browsers
	// do widely different things when pressing enter in designMode.
	select.insertNewlineAtCursor = function() {
	  insertAtCursor("<br>");
	};

	select.insertTabAtCursor = function() {
	  insertAtCursor(fourSpaces);
	};

	// Get the BR node at the start of the line on which the cursor
	// currently is, and the offset into the line. Returns null as
	// node if cursor is on first line.
	select.cursorPos = function(container, start) {
	  var range = selRange();
	  if (!range) return null;

	  var topNode = select.selectionTopNode(container, start);
	  while (topNode && !isBR(topNode))
		topNode = topNode.previousSibling;

	  var range2 = range.duplicate();
	  range.collapse(start);
	  if (topNode) {
		range2.moveToElementText(topNode);
		range2.collapse(false);
	  }
	  else {
		// When nothing is selected, we can get all kinds of funky errors here.
		try { range2.moveToElementText(container); }
		catch (e) { return null; }
		range2.collapse(true);
	  }
	  range.setEndPoint("StartToStart", range2);

	  return {node: topNode, offset: range.text.length};
	};

	select.setCursorPos = function(container, from, to) {
	  function rangeAt(pos) {
		var range = document.body.createTextRange();
		if (!pos.node) {
		  range.moveToElementText(container);
		  range.collapse(true);
		}
		else {
		  range.moveToElementText(pos.node);
		  range.collapse(false);
		}
		range.move("character", pos.offset);
		return range;
	  }

	  var range = rangeAt(from);
	  if (to && to != from)
		range.setEndPoint("EndToEnd", rangeAt(to));
	  range.select();
	}

	// Some hacks for storing and re-storing the selection when the editor loses and regains focus.
	select.getBookmark = function (container) {
	  var from = select.cursorPos(container, true), to = select.cursorPos(container, false);
	  if (from && to) return {from: from, to: to};
	};

	// Restore a stored selection.
	select.setBookmark = function(container, mark) {
	  if (!mark) return;
	  select.setCursorPos(container, mark.from, mark.to);
	};
  }
  // W3C model
  else {
	// Find the node right at the cursor, not one of its
	// ancestors with a suitable offset. This goes down the DOM tree
	// until a 'leaf' is reached (or is it *up* the DOM tree?).
	function innerNode(node, offset) {
	  while (node.nodeType != 3 && !isBR(node)) {
		var newNode = node.childNodes[offset] || node.nextSibling;
		offset = 0;
		while (!newNode && node.parentNode) {
		  node = node.parentNode;
		  newNode = node.nextSibling;
		}
		node = newNode;
		if (!newNode) break;
	  }
	  return {node: node, offset: offset};
	}

	// Store start and end nodes, and offsets within these, and refer
	// back to the selection object from those nodes, so that this
	// object can be updated when the nodes are replaced before the
	// selection is restored.
	select.markSelection = function () {
	  var selection = window.getSelection();
	  if (!selection || selection.rangeCount == 0)
		return (currentSelection = null);
	  var range = selection.getRangeAt(0);

	  currentSelection = {
		start: innerNode(range.startContainer, range.startOffset),
		end: innerNode(range.endContainer, range.endOffset),
		changed: false
	  };
	};

	select.selectMarked = function () {
	  var cs = currentSelection;
	  // on webkit-based browsers, it is apparently possible that the
	  // selection gets reset even when a node that is not one of the
	  // endpoints get messed with. the most common situation where
	  // this occurs is when a selection is deleted or overwitten. we
	  // check for that here.
	  function focusIssue() {
		if (cs.start.node == cs.end.node && cs.start.offset == cs.end.offset) {
		  var selection = window.getSelection();
		  if (!selection || selection.rangeCount == 0) return true;
		  var range = selection.getRangeAt(0), point = innerNode(range.startContainer, range.startOffset);
		  return cs.start.node != point.node || cs.start.offset != point.offset;
		}
	  }
	  if (!cs || !(cs.changed || (webkit && focusIssue()))) return;
	  var range = document.createRange();

	  function setPoint(point, which) {
		if (point.node) {
		  // Some magic to generalize the setting of the start and end
		  // of a range.
		  if (point.offset == 0)
			range["set" + which + "Before"](point.node);
		  else
			range["set" + which](point.node, point.offset);
		}
		else {
		  range.setStartAfter(document.body.lastChild || document.body);
		}
	  }

	  setPoint(cs.end, "End");
	  setPoint(cs.start, "Start");
	  selectRange(range);
	};

	// Helper for selecting a range object.
	function selectRange(range) {
	  var selection = window.getSelection();
	  if (!selection) return;
	  selection.removeAllRanges();
	  selection.addRange(range);
	}
	function selectionRange() {
	  var selection = window.getSelection();
	  if (!selection || selection.rangeCount == 0)
		return false;
	  else
		return selection.getRangeAt(0);
	}

	// Finding the top-level node at the cursor in the W3C is, as you
	// can see, quite an involved process.
	select.selectionTopNode = function(container, start) {
	  var range = selectionRange();
	  if (!range) return false;

	  var node = start ? range.startContainer : range.endContainer;
	  var offset = start ? range.startOffset : range.endOffset;
	  // Work around (yet another) bug in Opera's selection model.
	  if (window.opera && !start && range.endContainer == container && range.endOffset == range.startOffset + 1 &&
		  container.childNodes[range.startOffset] && isBR(container.childNodes[range.startOffset]))
		offset--;

	  // For text nodes, we look at the node itself if the cursor is
	  // inside, or at the node before it if the cursor is at the
	  // start.
	  if (node.nodeType == 3){
		if (offset > 0)
		  return topLevelNodeAt(node, container);
		else
		  return topLevelNodeBefore(node, container);
	  }
	  // Occasionally, browsers will return the HTML node as
	  // selection. If the offset is 0, we take the start of the frame
	  // ('after null'), otherwise, we take the last node.
	  else if (node.nodeName.toUpperCase() == "HTML") {
		return (offset == 1 ? null : container.lastChild);
	  }
	  // If the given node is our 'container', we just look up the
	  // correct node by using the offset.
	  else if (node == container) {
		return (offset == 0) ? null : node.childNodes[offset - 1];
	  }
	  // In any other case, we have a regular node. If the cursor is
	  // at the end of the node, we use the node itself, if it is at
	  // the start, we use the node before it, and in any other
	  // case, we look up the child before the cursor and use that.
	  else {
		if (offset == node.childNodes.length)
		  return topLevelNodeAt(node, container);
		else if (offset == 0)
		  return topLevelNodeBefore(node, container);
		else
		  return topLevelNodeAt(node.childNodes[offset - 1], container);
	  }
	};

	select.focusAfterNode = function(node, container) {
	  var range = document.createRange();
	  range.setStartBefore(container.firstChild || container);
	  // In Opera, setting the end of a range at the end of a line
	  // (before a BR) will cause the cursor to appear on the next
	  // line, so we set the end inside of the start node when
	  // possible.
	  if (node && !node.firstChild)
		range.setEndAfter(node);
	  else if (node)
		range.setEnd(node, node.childNodes.length);
	  else
		range.setEndBefore(container.firstChild || container);
	  range.collapse(false);
	  selectRange(range);
	};

	select.somethingSelected = function() {
	  var range = selectionRange();
	  return range && !range.collapsed;
	};

	select.offsetInNode = function(node) {
	  var range = selectionRange();
	  if (!range) return 0;
	  range = range.cloneRange();
	  range.setStartBefore(node);
	  return range.toString().length;
	};

	select.insertNodeAtCursor = function(node) {
	  var range = selectionRange();
	  if (!range) return;

	  range.deleteContents();
	  range.insertNode(node);
	  webkitLastLineHack(document.body);

	  // work around weirdness where Opera will magically insert a new
	  // BR node when a BR node inside a span is moved around. makes
	  // sure the BR ends up outside of spans.
	  if (window.opera && isBR(node) && isSpan(node.parentNode)) {
		var next = node.nextSibling, p = node.parentNode, outer = p.parentNode;
		outer.insertBefore(node, p.nextSibling);
		var textAfter = "";
		for (; next && next.nodeType == 3; next = next.nextSibling) {
		  textAfter += next.nodeValue;
		  removeElement(next);
		}
		outer.insertBefore(makePartSpan(textAfter, document), node.nextSibling);
	  }
	  range = document.createRange();
	  range.selectNode(node);
	  range.collapse(false);
	  selectRange(range);
	}

	select.insertNewlineAtCursor = function() {
	  select.insertNodeAtCursor(document.createElement("BR"));
	};

	select.insertTabAtCursor = function() {
	  select.insertNodeAtCursor(document.createTextNode(fourSpaces));
	};

	select.cursorPos = function(container, start) {
	  var range = selectionRange();
	  if (!range) return;

	  var topNode = select.selectionTopNode(container, start);
	  while (topNode && !isBR(topNode))
		topNode = topNode.previousSibling;

	  range = range.cloneRange();
	  range.collapse(start);
	  if (topNode)
		range.setStartAfter(topNode);
	  else
		range.setStartBefore(container);

	  var text = range.toString();
	  return {node: topNode, offset: text.length};
	};

	select.setCursorPos = function(container, from, to) {
	  var range = document.createRange();

	  function setPoint(node, offset, side) {
		if (offset == 0 && node && !node.nextSibling) {
		  range["set" + side + "After"](node);
		  return true;
		}

		if (!node)
		  node = container.firstChild;
		else
		  node = node.nextSibling;

		if (!node) return;

		if (offset == 0) {
		  range["set" + side + "Before"](node);
		  return true;
		}

		var backlog = []
		function decompose(node) {
		  if (node.nodeType == 3)
			backlog.push(node);
		  else
			forEach(node.childNodes, decompose);
		}
		while (true) {
		  while (node && !backlog.length) {
			decompose(node);
			node = node.nextSibling;
		  }
		  var cur = backlog.shift();
		  if (!cur) return false;

		  var length = cur.nodeValue.length;
		  if (length >= offset) {
			range["set" + side](cur, offset);
			return true;
		  }
		  offset -= length;
		}
	  }

	  to = to || from;
	  if (setPoint(to.node, to.offset, "End") && setPoint(from.node, from.offset, "Start"))
		selectRange(range);
	};
  }
})();

/* String streams are the things fed to parsers (which can feed them
 * to a tokenizer if they want). They provide peek and next methods
 * for looking at the current character (next 'consumes' this
 * character, peek does not), and a get method for retrieving all the
 * text that was consumed since the last time get was called.
 *
 * An easy mistake to make is to let a StopIteration exception finish
 * the token stream while there are still characters pending in the
 * string stream (hitting the end of the buffer while parsing a
 * token). To make it easier to detect such errors, the stringstreams
 * throw an exception when this happens.
 */

// Make a stringstream stream out of an iterator that returns strings.
// This is applied to the result of traverseDOM (see codemirror.js),
// and the resulting stream is fed to the parser.
var stringStream = function(source){
  // String that's currently being iterated over.
  var current = "";
  // Position in that string.
  var pos = 0;
  // Accumulator for strings that have been iterated over but not
  // get()-ed yet.
  var accum = "";
  // Make sure there are more characters ready, or throw
  // StopIteration.
  function ensureChars() {
	while (pos == current.length) {
	  accum += current;
	  current = ""; // In case source.next() throws
	  pos = 0;
	  try {current = source.next();}
	  catch (e) {
		if (e != StopIteration) throw e;
		else return false;
	  }
	}
	return true;
  }

  return {
	// peek: -> character
	// Return the next character in the stream.
	peek: function() {
	  if (!ensureChars()) return null;
	  return current.charAt(pos);
	},
	// next: -> character
	// Get the next character, throw StopIteration if at end, check
	// for unused content.
	next: function() {
	  if (!ensureChars()) {
		if (accum.length > 0)
		  throw "End of stringstream reached without emptying buffer ('" + accum + "').";
		else
		  throw StopIteration;
	  }
	  return current.charAt(pos++);
	},
	// get(): -> string
	// Return the characters iterated over since the last call to
	// .get().
	get: function() {
	  var temp = accum;
	  accum = "";
	  if (pos > 0){
		temp += current.slice(0, pos);
		current = current.slice(pos);
		pos = 0;
	  }
	  return temp;
	},
	// Push a string back into the stream.
	push: function(str) {
	  current = current.slice(0, pos) + str + current.slice(pos);
	},
	lookAhead: function(str, consume, skipSpaces, caseInsensitive) {
	  function cased(str) {return caseInsensitive ? str.toLowerCase() : str;}
	  str = cased(str);
	  var found = false;

	  var _accum = accum, _pos = pos;
	  if (skipSpaces) this.nextWhileMatches(/[\s\u00a0]/);

	  while (true) {
		var end = pos + str.length, left = current.length - pos;
		if (end <= current.length) {
		  found = str == cased(current.slice(pos, end));
		  pos = end;
		  break;
		}
		else if (str.slice(0, left) == cased(current.slice(pos))) {
		  accum += current; current = "";
		  try {current = source.next();}
		  catch (e) {if (e != StopIteration) throw e; break;}
		  pos = 0;
		  str = str.slice(left);
		}
		else {
		  break;
		}
	  }

	  if (!(found && consume)) {
		current = accum.slice(_accum.length) + current;
		pos = _pos;
		accum = _accum;
	  }

	  return found;
	},
	// Wont't match past end of line.
	lookAheadRegex: function(regex, consume) {
	  if (regex.source.charAt(0) != "^")
		throw new Error("Regexps passed to lookAheadRegex must start with ^");

	  // Fetch the rest of the line
	  while (current.indexOf("\n", pos) == -1) {
		try {current += source.next();}
		catch (e) {if (e != StopIteration) throw e; break;}
	  }
	  var matched = current.slice(pos).match(regex);
	  if (matched && consume) pos += matched[0].length;
	  return matched;
	},

	// Utils built on top of the above
	// more: -> boolean
	// Produce true if the stream isn't empty.
	more: function() {
	  return this.peek() !== null;
	},
	applies: function(test) {
	  var next = this.peek();
	  return (next !== null && test(next));
	},
	nextWhile: function(test) {
	  var next;
	  while ((next = this.peek()) !== null && test(next))
		this.next();
	},
	matches: function(re) {
	  var next = this.peek();
	  return (next !== null && re.test(next));
	},
	nextWhileMatches: function(re) {
	  var next;
	  while ((next = this.peek()) !== null && re.test(next))
		this.next();
	},
	equals: function(ch) {
	  return ch === this.peek();
	},
	endOfLine: function() {
	  var next = this.peek();
	  return next == null || next == "\n";
	}
  };
};

// A framework for simple tokenizers. Takes care of newlines and
// white-space, and of getting the text from the source stream into
// the token object. A state is a function of two arguments -- a
// string stream and a setState function. The second can be used to
// change the tokenizer's state, and can be ignored for stateless
// tokenizers. This function should advance the stream over a token
// and return a string or object containing information about the next
// token, or null to pass and have the (new) state be called to finish
// the token. When a string is given, it is wrapped in a {style, type}
// object. In the resulting object, the characters consumed are stored
// under the content property. Any whitespace following them is also
// automatically consumed, and added to the value property. (Thus,
// content is the actual meaningful part of the token, while value
// contains all the text it spans.)

function tokenizer(source, state) {
  // Newlines are always a separate token.
  function isWhiteSpace(ch) {
	// The messy regexp is because IE's regexp matcher is of the
	// opinion that non-breaking spaces are no whitespace.
	return ch != "\n" && /^[\s\u00a0]*$/.test(ch);
  }

  var tokenizer = {
	state: state,

	take: function(type) {
	  if (typeof(type) == "string")
		type = {style: type, type: type};

	  type.content = (type.content || "") + source.get();
	  if (!/\n$/.test(type.content))
		source.nextWhile(isWhiteSpace);
	  type.value = type.content + source.get();
	  return type;
	},

	next: function () {
	  if (!source.more()) throw StopIteration;

	  var type;
	  if (source.equals("\n")) {
		source.next();
		return this.take("whitespace");
	  }

	  if (source.applies(isWhiteSpace))
		type = "whitespace";
	  else
		while (!type)
		  type = this.state(source, function(s) {tokenizer.state = s;});

	  return this.take(type);
	}
  };
  return tokenizer;
}

/**
 * Storage and control for undo information within a CodeMirror
 * editor. 'Why on earth is such a complicated mess required for
 * that?', I hear you ask. The goal, in implementing this, was to make
 * the complexity of storing and reverting undo information depend
 * only on the size of the edited or restored content, not on the size
 * of the whole document. This makes it necessary to use a kind of
 * 'diff' system, which, when applied to a DOM tree, causes some
 * complexity and hackery.
 *
 * In short, the editor 'touches' BR elements as it parses them, and
 * the UndoHistory stores these. When nothing is touched in commitDelay
 * milliseconds, the changes are committed: It goes over all touched
 * nodes, throws out the ones that did not change since last commit or
 * are no longer in the document, and assembles the rest into zero or
 * more 'chains' -- arrays of adjacent lines. Links back to these
 * chains are added to the BR nodes, while the chain that previously
 * spanned these nodes is added to the undo history. Undoing a change
 * means taking such a chain off the undo history, restoring its
 * content (text is saved per line) and linking it back into the
 * document.
 */

// A history object needs to know about the DOM container holding the
// document, the maximum amount of undo levels it should store, the
// delay (of no input) after which it commits a set of changes, and,
// unfortunately, the 'parent' window -- a window that is not in
// designMode, and on which setTimeout works in every browser.
function UndoHistory(container, maxDepth, commitDelay, editor) {
  this.container = container;
  this.maxDepth = maxDepth; this.commitDelay = commitDelay;
  this.editor = editor;
  // This line object represents the initial, empty editor.
  var initial = {text: "", from: null, to: null};
  // As the borders between lines are represented by BR elements, the
  // start of the first line and the end of the last one are
  // represented by null. Since you can not store any properties
  // (links to line objects) in null, these properties are used in
  // those cases.
  this.first = initial; this.last = initial;
  // Similarly, a 'historyTouched' property is added to the BR in
  // front of lines that have already been touched, and 'firstTouched'
  // is used for the first line.
  this.firstTouched = false;
  // History is the set of committed changes, touched is the set of
  // nodes touched since the last commit.
  this.history = []; this.redoHistory = []; this.touched = []; this.lostundo = 0;
}

UndoHistory.prototype = {
  // Schedule a commit (if no other touches come in for commitDelay
  // milliseconds).
  scheduleCommit: function() {
	var self = this;
	parent.clearTimeout(this.commitTimeout);
	this.commitTimeout = parent.setTimeout(function(){self.tryCommit();}, this.commitDelay);
  },

  // Mark a node as touched. Null is a valid argument.
  touch: function(node) {
	this.setTouched(node);
	this.scheduleCommit();
  },

  // Undo the last change.
  undo: function() {
	// Make sure pending changes have been committed.
	this.commit();

	if (this.history.length) {
	  // Take the top diff from the history, apply it, and store its
	  // shadow in the redo history.
	  var item = this.history.pop();
	  this.redoHistory.push(this.updateTo(item, "applyChain"));
	  this.notifyEnvironment();
	  return this.chainNode(item);
	}
  },

  // Redo the last undone change.
  redo: function() {
	this.commit();
	if (this.redoHistory.length) {
	  // The inverse of undo, basically.
	  var item = this.redoHistory.pop();
	  this.addUndoLevel(this.updateTo(item, "applyChain"));
	  this.notifyEnvironment();
	  return this.chainNode(item);
	}
  },

  clear: function() {
	this.history = [];
	this.redoHistory = [];
	this.lostundo = 0;
  },

  // Ask for the size of the un/redo histories.
  historySize: function() {
	return {undo: this.history.length, redo: this.redoHistory.length, lostundo: this.lostundo};
  },

  // Push a changeset into the document.
  push: function(from, to, lines) {
	var chain = [];
	for (var i = 0; i < lines.length; i++) {
	  var end = (i == lines.length - 1) ? to : document.createElement("br");
	  chain.push({from: from, to: end, text: cleanText(lines[i])});
	  from = end;
	}
	this.pushChains([chain], from == null && to == null);
	this.notifyEnvironment();
  },

  pushChains: function(chains, doNotHighlight) {
	this.commit(doNotHighlight);
	this.addUndoLevel(this.updateTo(chains, "applyChain"));
	this.redoHistory = [];
  },

  // Retrieve a DOM node from a chain (for scrolling to it after undo/redo).
  chainNode: function(chains) {
	for (var i = 0; i < chains.length; i++) {
	  var start = chains[i][0], node = start && (start.from || start.to);
	  if (node) return node;
	}
  },

  // Clear the undo history, make the current document the start
  // position.
  reset: function() {
	this.history = []; this.redoHistory = []; this.lostundo = 0;
  },

  textAfter: function(br) {
	return this.after(br).text;
  },

  nodeAfter: function(br) {
	return this.after(br).to;
  },

  nodeBefore: function(br) {
	return this.before(br).from;
  },

  // Commit unless there are pending dirty nodes.
  tryCommit: function() {
	if (!window || !window.parent || !window.UndoHistory) return; // Stop when frame has been unloaded
	if (this.editor.highlightDirty()) this.commit(true);
	else this.scheduleCommit();
  },

  // Check whether the touched nodes hold any changes, if so, commit
  // them.
  commit: function(doNotHighlight) {
	parent.clearTimeout(this.commitTimeout);
	// Make sure there are no pending dirty nodes.
	if (!doNotHighlight) this.editor.highlightDirty(true);
	// Build set of chains.
	var chains = this.touchedChains(), self = this;

	if (chains.length) {
	  this.addUndoLevel(this.updateTo(chains, "linkChain"));
	  this.redoHistory = [];
	  this.notifyEnvironment();
	}
  },

  // [ end of public interface ]

  // Update the document with a given set of chains, return its
  // shadow. updateFunc should be "applyChain" or "linkChain". In the
  // second case, the chains are taken to correspond the the current
  // document, and only the state of the line data is updated. In the
  // first case, the content of the chains is also pushed iinto the
  // document.
  updateTo: function(chains, updateFunc) {
	var shadows = [], dirty = [];
	for (var i = 0; i < chains.length; i++) {
	  shadows.push(this.shadowChain(chains[i]));
	  dirty.push(this[updateFunc](chains[i]));
	}
	if (updateFunc == "applyChain")
	  this.notifyDirty(dirty);
	return shadows;
  },

  // Notify the editor that some nodes have changed.
  notifyDirty: function(nodes) {
	forEach(nodes, method(this.editor, "addDirtyNode"))
	this.editor.scheduleHighlight();
  },

  notifyEnvironment: function() {
	if (this.onChange) this.onChange(this.editor);
	// Used by the line-wrapping line-numbering code.
	if (window.frameElement && window.frameElement.CodeMirror.updateNumbers)
	  window.frameElement.CodeMirror.updateNumbers();
  },

  // Link a chain into the DOM nodes (or the first/last links for null
  // nodes).
  linkChain: function(chain) {
	for (var i = 0; i < chain.length; i++) {
	  var line = chain[i];
	  if (line.from) line.from.historyAfter = line;
	  else this.first = line;
	  if (line.to) line.to.historyBefore = line;
	  else this.last = line;
	}
  },

  // Get the line object after/before a given node.
  after: function(node) {
	return node ? node.historyAfter : this.first;
  },
  before: function(node) {
	return node ? node.historyBefore : this.last;
  },

  // Mark a node as touched if it has not already been marked.
  setTouched: function(node) {
	if (node) {
	  if (!node.historyTouched) {
		this.touched.push(node);
		node.historyTouched = true;
	  }
	}
	else {
	  this.firstTouched = true;
	}
  },

  // Store a new set of undo info, throw away info if there is more of
  // it than allowed.
  addUndoLevel: function(diffs) {
	this.history.push(diffs);
	if (this.history.length > this.maxDepth) {
	  this.history.shift();
	  this.lostundo += 1;
	}
  },

  // Build chains from a set of touched nodes.
  touchedChains: function() {
	var self = this;

	// The temp system is a crummy hack to speed up determining
	// whether a (currently touched) node has a line object associated
	// with it. nullTemp is used to store the object for the first
	// line, other nodes get it stored in their historyTemp property.
	var nullTemp = null;
	function temp(node) {return node ? node.historyTemp : nullTemp;}
	function setTemp(node, line) {
	  if (node) node.historyTemp = line;
	  else nullTemp = line;
	}

	function buildLine(node) {
	  var text = [];
	  for (var cur = node ? node.nextSibling : self.container.firstChild;
		   cur && (!isBR(cur) || cur.hackBR); cur = cur.nextSibling)
		if (!cur.hackBR && cur.currentText) text.push(cur.currentText);
	  return {from: node, to: cur, text: cleanText(text.join(""))};
	}

	// Filter out unchanged lines and nodes that are no longer in the
	// document. Build up line objects for remaining nodes.
	var lines = [];
	if (self.firstTouched) self.touched.push(null);
	forEach(self.touched, function(node) {
	  if (node && (node.parentNode != self.container || node.hackBR)) return;

	  if (node) node.historyTouched = false;
	  else self.firstTouched = false;

	  var line = buildLine(node), shadow = self.after(node);
	  if (!shadow || shadow.text != line.text || shadow.to != line.to) {
		lines.push(line);
		setTemp(node, line);
	  }
	});

	// Get the BR element after/before the given node.
	function nextBR(node, dir) {
	  var link = dir + "Sibling", search = node[link];
	  while (search && !isBR(search))
		search = search[link];
	  return search;
	}

	// Assemble line objects into chains by scanning the DOM tree
	// around them.
	var chains = []; self.touched = [];
	forEach(lines, function(line) {
	  // Note that this makes the loop skip line objects that have
	  // been pulled into chains by lines before them.
	  if (!temp(line.from)) return;

	  var chain = [], curNode = line.from, safe = true;
	  // Put any line objects (referred to by temp info) before this
	  // one on the front of the array.
	  while (true) {
		var curLine = temp(curNode);
		if (!curLine) {
		  if (safe) break;
		  else curLine = buildLine(curNode);
		}
		chain.unshift(curLine);
		setTemp(curNode, null);
		if (!curNode) break;
		safe = self.after(curNode);
		curNode = nextBR(curNode, "previous");
	  }
	  curNode = line.to; safe = self.before(line.from);
	  // Add lines after this one at end of array.
	  while (true) {
		if (!curNode) break;
		var curLine = temp(curNode);
		if (!curLine) {
		  if (safe) break;
		  else curLine = buildLine(curNode);
		}
		chain.push(curLine);
		setTemp(curNode, null);
		safe = self.before(curNode);
		curNode = nextBR(curNode, "next");
	  }
	  chains.push(chain);
	});

	return chains;
  },

  // Find the 'shadow' of a given chain by following the links in the
  // DOM nodes at its start and end.
  shadowChain: function(chain) {
	var shadows = [], next = this.after(chain[0].from), end = chain[chain.length - 1].to;
	while (true) {
	  shadows.push(next);
	  var nextNode = next.to;
	  if (!nextNode || nextNode == end)
		break;
	  else
		next = nextNode.historyAfter || this.before(end);
	  // (The this.before(end) is a hack -- FF sometimes removes
	  // properties from BR nodes, in which case the best we can hope
	  // for is to not break.)
	}
	return shadows;
  },

  // Update the DOM tree to contain the lines specified in a given
  // chain, link this chain into the DOM nodes.
  applyChain: function(chain) {
	// Some attempt is made to prevent the cursor from jumping
	// randomly when an undo or redo happens. It still behaves a bit
	// strange sometimes.
	var cursor = select.cursorPos(this.container, false), self = this;

	// Remove all nodes in the DOM tree between from and to (null for
	// start/end of container).
	function removeRange(from, to) {
	  var pos = from ? from.nextSibling : self.container.firstChild;
	  while (pos != to) {
		var temp = pos.nextSibling;
		removeElement(pos);
		pos = temp;
	  }
	}

	var start = chain[0].from, end = chain[chain.length - 1].to;
	// Clear the space where this change has to be made.
	removeRange(start, end);

	// Insert the content specified by the chain into the DOM tree.
	for (var i = 0; i < chain.length; i++) {
	  var line = chain[i];
	  // The start and end of the space are already correct, but BR
	  // tags inside it have to be put back.
	  if (i > 0)
		self.container.insertBefore(line.from, end);

	  // Add the text.
	  var node = makePartSpan(fixSpaces(line.text));
	  self.container.insertBefore(node, end);
	  // See if the cursor was on this line. Put it back, adjusting
	  // for changed line length, if it was.
	  if (cursor && cursor.node == line.from) {
		var cursordiff = 0;
		var prev = this.after(line.from);
		if (prev && i == chain.length - 1) {
		  // Only adjust if the cursor is after the unchanged part of
		  // the line.
		  for (var match = 0; match < cursor.offset &&
			   line.text.charAt(match) == prev.text.charAt(match); match++){}
		  if (cursor.offset > match)
			cursordiff = line.text.length - prev.text.length;
		}
		select.setCursorPos(this.container, {node: line.from, offset: Math.max(0, cursor.offset + cursordiff)});
	  }
	  // Cursor was in removed line, this is last new line.
	  else if (cursor && (i == chain.length - 1) && cursor.node && cursor.node.parentNode != this.container) {
		select.setCursorPos(this.container, {node: line.from, offset: line.text.length});
	  }
	}

	// Anchor the chain in the DOM tree.
	this.linkChain(chain);
	return start;
  }
};

/* A few useful utility functions. */

// Capture a method on an object.
function method(obj, name) {
  return function() {obj[name].apply(obj, arguments);};
}

// The value used to signal the end of a sequence in iterators.
var StopIteration = {toString: function() {return "StopIteration"}};

// Apply a function to each element in a sequence.
function forEach(iter, f) {
  if (iter.next) {
	try {while (true) f(iter.next());}
	catch (e) {if (e != StopIteration) throw e;}
  }
  else {
	for (var i = 0; i < iter.length; i++)
	  f(iter[i]);
  }
}

// Map a function over a sequence, producing an array of results.
function map(iter, f) {
  var accum = [];
  forEach(iter, function(val) {accum.push(f(val));});
  return accum;
}

// Create a predicate function that tests a string againsts a given
// regular expression. No longer used but might be used by 3rd party
// parsers.
function matcher(regexp){
  return function(value){return regexp.test(value);};
}

// Test whether a DOM node has a certain CSS class.
function hasClass(element, className) {
  var classes = element.className;
  return classes && new RegExp("(^| )" + className + "($| )").test(classes);
}
function removeClass(element, className) {
  element.className = element.className.replace(new RegExp(" " + className + "\\b", "g"), "");
  return element;
}

// Insert a DOM node after another node.
function insertAfter(newNode, oldNode) {
  var parent = oldNode.parentNode;
  parent.insertBefore(newNode, oldNode.nextSibling);
  return newNode;
}

function removeElement(node) {
  if (node.parentNode)
	node.parentNode.removeChild(node);
}

function clearElement(node) {
  while (node.firstChild)
	node.removeChild(node.firstChild);
}

// Check whether a node is contained in another one.
function isAncestor(node, child) {
  while (child = child.parentNode) {
	if (node == child)
	  return true;
  }
  return false;
}

// The non-breaking space character.
var nbsp = "\u00a0";
var matching = {"{": "}", "[": "]", "(": ")",
				"}": "{", "]": "[", ")": "("};

// Standardize a few unportable event properties.
function normalizeEvent(event) {
  if (!event.stopPropagation) {
	event.stopPropagation = function() {this.cancelBubble = true;};
	event.preventDefault = function() {this.returnValue = false;};
  }
  if (!event.stop) {
	event.stop = function() {
	  this.stopPropagation();
	  this.preventDefault();
	};
  }

  if (event.type == "keypress") {
	event.code = (event.charCode == null) ? event.keyCode : event.charCode;
	event.character = String.fromCharCode(event.code);
  }
  return event;
}

// Portably register event handlers.
function addEventHandler(node, type, handler, removeFunc) {
  function wrapHandler(event) {
	handler(normalizeEvent(event || window.event));
  }
  if (typeof node.addEventListener == "function") {
	node.addEventListener(type, wrapHandler, false);
	if (removeFunc) return function() {node.removeEventListener(type, wrapHandler, false);};
  }
  else {
	node.attachEvent("on" + type, wrapHandler);
	if (removeFunc) return function() {node.detachEvent("on" + type, wrapHandler);};
  }
}

function nodeText(node) {
  return node.textContent || node.innerText || node.nodeValue || "";
}

function nodeTop(node) {
  var top = 0;
  while (node.offsetParent) {
	top += node.offsetTop;
	node = node.offsetParent;
  }
  return top;
}

function isBR(node) {
  var nn = node.nodeName;
  return nn == "BR" || nn == "br";
}
function isSpan(node) {
  var nn = node.nodeName;
  return nn == "SPAN" || nn == "span";
}
